6th Gear Syncros going after 5K.
 

Just thought I'd share that I have experienced an issue with the transmission of my 370Z. I think the syncros for 6th are going. I first noticed it when I drove to San Antonio for work and suddenly was scratching going into 6th. Then I noticed that the higher the revs I'm pulling when I go into 6th, the worse it is. That means that a 4-6 upshift will scratch more than a 5-6, and a 3-6 is even worse. I've scheduled a dropoff at a dealership back in Houston tomorrow. I will update you guys, but hopefully it's just an issue with mine since these transmissions have pretty much been in production for years.

A buddy of mine suggested the SyncroRevMatch (SRM) feature, but SRM is really like a overhyped cruise control feature that actuates the throttle and doesn't really do anything to the transmission.

Yeah, the SRM doesn't have anything to do with it, it's controlling the engine which is on the other side of the clutch.

I have a hard time getting mine into 6th sometimes. It doesn't grind but it hangs up on something.

Note that there are less syncro's on the higher gears than there are on the lower ones. 1st and 2nd have 3 syncros, 3rd and 4th have 2. Can't remember off the top of my head but 6th may only have 1.

One possibility is that your clutch isn't fully disengaging. If you are getting grinding of any sort when the clutch pedal is on the floor this could be the case. Does your clutch take up seem like it's right on the floor?

The clutch disengages fine for all of the gears but sixth. The action is high, not low as if the clutch isn't lifting, but I'm sure they'll check the tolerances when they have it apart. Doing a slow, kind of double-clutching, shift-pause-shift will allow you to put it into sixth with no scratching. It's at the dealership right now. I have to wait until Monday to hear back from them. I'll keep you guys updated.

Update
 

I told you guys I'd keep you posted. Nissan is replacing the transmission and I should have my car by Wednesday evening at the latest. I think this is a fluke and I was unfortunate to have had this happen, but am fairly sure it is an isolated incident.

One a related note, the base Sentra SUCKS (would buy a Mazda3i over it every time), but the CVT on the small displacement engines makes them really peppy.

Okay, great. Let us know how it feels after you get it back.

Did they give you the reason why the transmission needed replacement?

Yes, more information is needed about their reasoning for the replacement.

Oh good god.. I hope this isn't a trend.

I have a '04 G35 Coupe.. and have been through 3 replacement transmissions (4 total), and am waiting for this one to do the same thing, as it's always under 20k miles.. the quickest happening in less than 10k. (I was not alone with similar issues according to the popular boards.)

It starts by 5th or 6th grinding on quicker shifts, regardless of the clutch being fully depressed, and consistently got worse after time.

I will say I haven't had any issues getting things taken care of by Infiniti.. they happily replaced the transmission over and over again, with loaner cars and no tremendous hassle on my part, but I would hope that this synchro issue would have been resolved.

I was unable to get firm information on what the problem was, as the dealer would recognize the problem, and initiate the 'fix'.. aka a new transmission.

But this could absolutely be completely irrelevant, and unrelated.. I do not have detailed info on the differences in the two transmissions.

Sentra? Is that the loaner? I was always given a G35 Sedan.. I get that it's Infiniti vs. Nissan.. but a 35k car is the same.. a Maxima maybe?

Although.. we have a 6MT Sentra here at STILLEN.. with some goodies on it, including the loudest f'ing exhaust evar.. and it's yellow and black.. which makes it kind of fun to drive.. the BUMBLEBEE! ;)

STILLEN : Project Vehicles - STILLEN Nissan Sentra SE-R Spec V

Thanks for the replies.

The guy I'm dealt with wouldn't know a syncro from a loaf pan, so I didn't bother. I'll ask the tech when I get it back.

As for the Sentra, it's not a loaner, it's a rental and I had to pay for it up front because the dealership couldn't confirm that Nissan would pay for the repair. Next time (which I'm hoping there won't be) I will demand they pay for it from the start and that they provide an 'equivalent or better' car in the meantime. I nearly called NNA when they said they wouldn't provide the rental up front, but I had to get back to San Antonio by Monday and it wasn't worth the hassle this time. They've already agreed to pick up the bill on the Sentra.

by any chance when you were in 6th gear did it make like a whining noise as you increased your RPMs..? as mine does and im not sure if this is normal

im sorry to have to inform you, but this is not an isolated incident. unfortunatley, the same thing is happening to my car right now. they keep telling me that theres nothing wrong with the car. its doing it from 4-6 and 5-6. they say "im shifting too fast". i think im just gonna have to wait till it gets worse

It was definitely amplified when going two gears in all of my experiences with it. It will continue to get louder and happen more frequently.. eventually getting to the point where no matter how slow you attempt to engage the gear it will grind..

That's disheartening..

I wonder if the new location of the transmission is causing a heat problem?

On a side note Honda replaced a lot of transmissions in the early NSX due to a snap ring issue.

Oh joy,

I drove my 370 from Houston - Austin to drop it off at UpRev today and I noticed second gear increasingly difficult to get into. I felt like I was raping it every time. Kinda made me sick to hear that but I thought maybe I was doing something wrong. I also did notice 6th to be a bit of a biotch to get into sometimes but 2nd just seems way off.:ugh2:

My G37s just had the Tranny replaced also. It also started with quick 5th to 6th shifts.

i went to two nissan dealorships and they bothsaid they wouldnt replace it. said it was my fault, that im damaging the transmission by shifting from 4-6. i voided my warranty by going from accelerating to cruising? BS

If you're getting it from 4-6, it won't be long before it's 4-5 and 5-6.. But that's crap. Nissan is fully aware they have synchro issues on 6MT's, I'm just surprised it's lived through the G37 and now to the 370Z..

They have replaced a LOT of transmissions.. for me alone 3 replacements..

That's one to remember. It sounds like one should wait until the grinding happens in a 5-6 shift, and then go to the dealer and complain.

thats a good idea exept im gonna have to go to one thats like and hour away from where i live to get it looked at now since nissan has me "in their books".

So it's bad on the trany to go from 4-6? I have always skipped in my old 5 speed doing 3-5 without problems.

That has got to be one of the most ANNOYING ANNOYING ANNOYING pieces of bullsh!t I've ever heard in my entire life :shakes head:

NAME & SHAME those dealers - they care so little for their customers that they don't deserve to sell another car - EVER.

How DARE they deny your reasonable claim on those grounds? Phone Nissan Customer Care and speak to a manager about it. Write a letter of complaint to the CEO of Nissan North America, copy it to Carlos Ghosn, copy it to all the campaigning TV shows you can think of, put a video on YouTube and then post it here in a new thread, so we can make a big thing of it. Give these ****s as much bad publicity as they deserve.

Who did you say they were again?...

The nissan dealorship in temple, tx. They were very rude to me about it too. I don't think I could do all that though, since I'm in the army I might get in trouble with going to the press and all.

I've never heard that it's bad to skip gears.. EVER.. I'd say they were feeding you a load of crap. I've skipped gears on many, many cars.. for many, many years without any weird things happening. Sometimes 5th and 6th ratios are so close, when cruising it's almost a waste of time upshifting through all the gears.

Nissan dealership in Temple, tx - YOU SHOULD BE ASHAMED OF YOURSELVES

I hope nobody ever buys a car from you, ever again.

Chubbs, you're right, these guys should never be able to sell another car to any other unfortunate soul that might have to deal with them. Screw those guys. I've been skipping gears on 5spd and 6spd cars for the last 10 years and have never heard of such BS!!

That's what I told them. The service advisor said that he's never dricin a car like that or known anybody that has. He also said that it says in the car manual the shift the gears in numerical sequence

Somebody needs to come out with a bad *** aftermarket transmission!

I would tell the dealer you and Nissan are even. They skipped the oil cooler and you skipped a gear.

:iagree: Now thats just damn straight forward!

Update
 

Well, I got the car back a couple days ago. They replaced the transmission, but the guy at the dealership was trying to lecture me that Nissan wants people to drive sequentially to avoid this wearing syncro issue. It's possible that a company offering a beefed up fifth and sixth gear stands to make quite a bit of money off of the out-of-warranty 6MT owners. In the DSM community, TRE and John Shepherd were well known for their awesome aftermarket transmissions.

Doesn't make sense... are you experiencing grinding and clunk getting in all gears prior to this issue? I have to shift slower now just to baby the gearbox. [sigh]

well the people that ive talked to at nissan say that shifting from 4-6 only hurts it if you do it realy fast. so if your gonna skip a gear, wait to put it in 6th until right after the rpms start going down. this will make the synchros wear down alot slower. but if your not skipping gears it could still happen. just remember, unless your "getting on it" you really dont need to shift very fast.

Those things might make the problem worse faster, but a transmission having consistent issues with this kind of mileage (below 10K!) has serious design flaws. Josh - 3 replacements in warranty would make me afraid to own the car out of warranty - are you going to sell it?

I've been chomping at the bit to get this car on the 15th of May, but this is a big enough issue that I'm not even sure I want it. My whole reason for getting a new car is to avoid having random broken crap to deal with on a regular basis, and what I consider to be a major transmission issue is just BS.

Just to throw in a little perspective, non-supercharged MINIs have had a similar problem. On MY2002-2005 MINI Coopers, the gearbox was made by "Midlands" in the UK, and this gearbox was a real POS as it turns out. Many, many of them started shifting funny, and more than a few puked their guts out. MINI (BMW actually) has never admitted that there was a problem, though they did switch to a bulletproof Getrag transmission for 2006.

I helped a friend of mine install a new Midlands out of warrantee, and a year later, it selected two gears at once and cracked wide open. Nice. After that, we figured out how to put a Cooper S 6-speed in the car (a Getrag unit) and that did the trick.

So the point is, I have my doubts as to whether Nissan would ever come right out and admit that the 370Z gearbox has issues. They'll more likely deal with each customer individually through the dealer network. That means, unfortunately, that some will get three gearboxes, and some will be treated like the morons that they certainly are not.

Christ! Im about to cut my losses and just buy a used 350Z! It sounds like Nissan is dropping the ball a bit with the 370!

While getting three new transmissions would be more of a pain than I want to deal with (even if the dealer is nice about it), I worry more about having to buy a transmission every 15K miles after the warranty is up. I guess the moral is that if you have gone through more than one transmission by the time the warranty is about to expire, you sell the car :ugh2:

I can't wait for the tranny to go again.. just turned 80k.. and it's out of warranty.. but there is no way they would have replaced transmissions religiously within 20k miles and not do it with me even out of warranty.

I trust they will take care of it, and if not, that will be a different conversation.

Technically it's just out of the lemon law world, as the first occurrence was at 19k.. but 18k miles isn't set in stone, it's more of a reference according to what I've read. There is a problem, the problem repeated, their fix to the problem was replacing the transmission, over and over again..

This is the only problem I've had with the car, I would have hoped it would have been resolved 5 years later with a new model, new engine, etc.

Sounds more like you want to justify an inferior purchase. The 370 is far better engineered in every aspect than the 350Z and the transmission is nearly identical including the syncros that went bad on mine. It's to be expected that if you drive like I do, with hard accelerationg and then just throw it in a higher gear and let the syncros sort it out, you are going to wear them out. You would in a 350Z just as well as the 370Z or any other car with this or a lesser transmission. Nissan didn't drop the ball any more or than anyone else so just step back from the ledge and don't worry about it.

I don't slam gears ever and shift a lot slower from 4 or three to 6 than I would 5 to 6. I'm a bit more careful now and am watching to ensure that the transmission shifts as well as it did before this issue surfaced.